Switch devices, control devices and steering systems of the above-mentioned type are known from the prior art. To operate an electric motor it is common practice to activate the individual phases of the electric motor by means of semiconductor half-bridges. These half-bridges each have two semiconductor switches, a high side switch and a low side switch, which can be activated by a pulse-width modulation, in order to energize the phase in accordance with the specified pulse-width modulation. By means of a driver device, often referred to as a gate driver, the semiconductor switches are actuated, in order to pass current or to disconnect a flow of current.
To ensure the continuous safe operation of electric motors in safety-critical applications, it is also known to provide and control such electric motors in a redundant manner so that, for example, one phase of the electric motor is provided multiple times. In the field of steering systems, which are designed to provide electric-motor based support for the driver or an electric-motor based steering angle adjustment independently of the driver in an autonomous driving mode, it is known to provide a plurality of phases redundantly and to control each of these phases by means of a separate semiconductor half-bridge. In order that no incorrect moments or the like can occur in normal operation, the semiconductor switches or the semiconductor half-bridges must be switched at the same time. To achieve this, it is known to connect each of the half-bridges, or each of the semiconductor switches, to a control unit separately to feed an activation signal thereto, so that a safe operation is guaranteed even in the event of failure of one of the phases or one of the semiconductor switches. However, this means high wiring costs, which both places constraints on the available installation space as well as leading to unwanted material and assembly costs. A corresponding control device is known, for example, from the patent specification US 2004/0264075 A1.